Allow tool unit tests to provide multiple files to test against.
Review Request #11653 — Created June 12, 2021 and submitted
This adds an
specifies a mapping of filenames to file contents. These files will be
written to the tree, allowing the tool to access those files. This is
mostly useful for full-repository unit tests.
When provided, the returned tuple will contain a mapping of filenames to
Fileentries, rather than a single
Used this along with the upcoming unit tests for Cargo.